DNAC Pools for Automation and IP Handoff

[ChrisNewnham_]

Hello, I was wondering if there were minimum pool requirements for both the LAN Automation and IP Handoff pools.

LAN Automation

For LAN Automation, I believe the formula for calculating the number of IPs (when using 2 interfaces per device) required is:

(<number of devices> * 2)  * 4

As it reserves 2 addresses for each device (loopback and VLAN 1), plus 4 addresses per /30 pool. So 80 IPs required for 10 devices. (see https://www.cisco.com/c/en/us/td/docs/cloud-systems-management/network-automation-and-management/dna-center/tech_notes/b_dnac_sda_lan_automation_deployment.html)

However I think there's a hard limit of a /25 as the smallest pool available, as it checks that 128 IPs are free before beginning? https://www.cisco.com/c/en/us/td/docs/solutions/CVD/Campus/cisco-sda-design-guide.html#IPAddressPoolPlanningforLANAutomation

IP Handoff

Is there a minimum size for this? Is it just 1 /30 for each VN that you want to route to the fusion device?

Thanks

[Preston Chilcote]

I don't know all the details of how to calculate the number of IPs used, but I wanted to share what I recently learned, that the next Cisco DNA release will allow for smaller IP address pools of /27, /28 or /29 for smaller deployments.  I believe /26 is the current smallest pool allowed.

[Sylvain_Che]

Hi @ChrisNewnham_ ,

LAN Auto:

From a 2021 webinar, Cisco provided the following formula to calculate the number of IP addresses needed for LAN Automation:

Number of discovered devices=(0,703*no_of_ip_address_in_pool - 3) /5

For the smallest subnet size possible, please refer to Preston's reply.

L3 Handoff:

Until now, /30 subnets were created by DNAC when configuring L3Handoff.

With the new DNAC release (2.3.5 I believe), it is now possible to define your own subnet size.

Regards,

Sylvain.